A Pilot Study of Viscoelastic Monitoring in Pediatric Trauma: Outcomes and Lessons Learned

Background:

Examine the characteristics and outcomes of pediatric trauma patients at risk for coagulopathy following implementation of viscoelastic monitoring.

Materials and Methods:

Injured children, aged <18 years, from September 7, 2014, to December 21, 2015, at risk for trauma-induced coagulopathy were identified from a single, level-1 American College of Surgeons verified pediatric trauma center. Patients were grouped by coagulation assessment: no assessment (NA), conventional coagulation testing alone (CCT), and conventional coagulation testing with rapid thromboelastography (rTEG). Coagulation assessment was provider preference with all monitoring options continuously available. Groups were compared and outcomes were evaluated including blood product utilization, Intensive Care Unit (ICU) utilization, duration of mechanical ventilation, and mortality.

Results:

A total of 155 patients were identified (NA = 78, CCT = 54, and rTEG = 23). There was no difference in age, gender, race, or mechanism. In practice, rTEG patients were more severely injured, more anemic, and received more blood products and crystalloid (P < 0.001). rTEG patients also had increased mortality with fewer ventilator and ICU-free days. Multivariate logistic regression and covariance analysis indicated that while rTEG use was not associated with mortality, it was associated with increased use of blood products, duration of mechanical ventilation, and ICU length of stay.

Conclusions:

Viscoelastic monitoring was infrequently performed, but utilized in more severely injured patients. Well-designed prospective studies in patients at high risk of coagulopathy are needed to evaluate goal-directed hemostatic resuscitation strategies in children.

Assessment of hemostatic changes in a model of acute hemorrhage in dogs

OBJECTIVE

To evaluate hemostatic changes following experimental acute hemorrhage in dogs using traditional coagulation tests (eg, platelet count, prothrombin time [PT], and activated partial thromboplastin time [aPTT]), kaolin-activated thromboelastography (TEG), and whole blood multiple electrode impedance platelet aggregometry.

DESIGN

Prospective study.

SETTING

Research laboratory.

ANIMALS

Five Beagles.

INTERVENTIONS

Dogs were anesthetized prior to obtaining blood samples for baseline PCV, total plasma protein (TPP), arterial blood-gas, platelet count, PT, aPTT, TEG, fibrinogen, and aggregometry. Blood was obtained at 4 additional time points, following 20% blood volume loss, 40% blood volume loss, 60 minutes of sustained hypotension, and after autologous blood transfusion. In addition, heart rate and direct arterial blood pressure were measured at each time point.

MEASUREMENTS AND MAIN RESULTS

Significant decreases were noted for PCV (P = 0.048), TPP (P < 0.0001), and arterial blood pressures (P < 0.0001) over time. Platelet count did not change significantly (P = 0.879), but platelet function was decreased following hemorrhage when arachidonic acid (P = 0.004) and ADP (P = 0.008) were used as agonists. The TEG variables R (P = 0.030), MA (P = 0.043), and G (P = 0.037) were significantly, albeit mildly, changed following hemorrhage. Significant prolongations in PT (P < 0.0001) and aPTT (P = 0.041), and decreases in fibrinogen concentration (P = 0.002) were also seen.

CONCLUSION

Platelet dysfunction occurred following hemorrhage in this model, despite a stable platelet count. Additionally, significant changes associated with hemorrhage were documented in aPTT, fibrinogen, and MA. Platelet function testing in dogs with naturally occurring hemorrhage warrants further investigation.